Changes in diel diving patterns accompany shifts between northern foraging and southward migration in leatherback turtles

2006 ◽  
Vol 84 (5) ◽  
pp. 754-765 ◽  
Author(s):  
M.C. James ◽  
C.A. Ottensmeyer ◽  
S.A. Eckert ◽  
R.A. Myers

Diel diving patterns have been widely documented among plankton-feeding marine vertebrates. In many cases, these patterns have been interpreted as a response to the diel vertical migrations of prey. The leatherback turtle, Dermochelys coriacea (Vandelli, 1761), is a large marine predator that exploits gelatinous plankton in disparate foraging areas. Individuals of this species spend extended periods at northern latitudes before moving southward through pelagic waters. To identify and compare potential diel patterns of diving behaviour in temperate areas, where foraging has been observed, versus during southward migration, 15 subadult and adult leatherbacks were equipped with satellite-linked time–depth recorders off Nova Scotia, Canada. We observed variation in nocturnal versus diurnal behaviour, both at northern latitudes and during migration; however, diel differences in both diving and surface activity were much less pronounced while leatherbacks were in the north. We interpret the difference in leatherback diel diving regimen to reflect a response to changing resource conditions at these times, with leatherbacks foraging throughout the day and night at high latitudes, then changing to a bimodal pattern of diving during southward migration, with generally longer, deeper diving occurring during the night versus during the day. By quantifying diel changes in leatherback behaviour, we provide the first surface time correction factors based on multiple individuals for use in estimating abundance from aerial surveys.

Oryx ◽  
2004 ◽  
Vol 38 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Sebastian Troëng ◽  
Didiher Chacón ◽  
Belinda Dick

Leatherback turtle Dermochelys coriacea nesting has declined on Pacific beaches and as a result the species is considered Critically Endangered. Atlantic populations are, however, also important for the species' survival and therefore we undertook a study to quantify the size and nesting trend of the Caribbean Costa Rica and Panama leatherback turtle rookery. Tag returns show that post-nesting females from the rookery disperse throughout the Caribbean, Gulf of Mexico and North Atlantic. Aerial and track survey results were used to estimate 5,759–12,893 nests per year between San Juan river and Chiriquí beach, making this the fourth largest rookery worldwide. Monitoring results from three beaches (Tortuguero, Pacuare and Gandoca) were used to examine any temporal trend in nesting using nonparametric regression. Nesting appeared to decline slightly from 1995 to 2003 but the trend could be an artefact of interannual variation in nest numbers. Explanations for the difference in nesting trends over the past 15 years for Pacific (rapid decline) and Caribbean (slight decline or stable) rookeries include: (1) hatching success on Caribbean beaches has been higher due to dispersed nesting, (2) fisheries bycatch has been greater in the Pacific, and (3) less overlap between fishing areas and leatherback turtle habitats in the Atlantic. Quantification of human-caused mortality of all life stages and knowledge of the marine habitats used by Atlantic leatherback turtles are required to facilitate the development and implementation of effective strategies to reduce threats and avoid a repeat of the decline that has occurred in the Pacific population.


Oryx ◽  
2012 ◽  
Vol 46 (3) ◽  
pp. 348-358 ◽  
Author(s):  
Ohiana Revuelta ◽  
Yolanda M. León ◽  
Pablo Feliz ◽  
Brendan J. Godley ◽  
Juan A. Raga ◽  
...  

AbstractNesting by marine turtles in the Caribbean has declined considerably, mainly because of human exploitation, but there has previously been no monitoring in the Dominican Republic. We present the first detailed assessment of the status of marine turtle nesting in the country, based on surveys during 2006–2010. Nesting populations of hawksbill Eretmochelys imbricata and leatherback turtle Dermochelys coriacea are of regional importance and the green turtle Chelonia mydas is still present, although nesting in low numbers. The two main nesting sites are within protected areas: the Jaragua National Park in the south-west, important for leatherback turtles (mean of 126 nests per season), and Del Este National Park on Saona Island in the south-east, principally for hawksbill turtles (mean of 100 nests per season). Comparison with historical data suggests all rookeries are profoundly reduced in size. Although the main nesting beaches are within protected areas, illegal egg-take and meat consumption continues there, and also elsewhere in the country.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Daniela Rojas-Cañizales ◽  
Nínive Espinoza-Rodríguez ◽  
María Alejandra Rodríguez ◽  
Jordano Palmar ◽  
María Gabriela Montiel-Villalobos ◽  
...  

Leatherback turtle (Dermochelys coriacea) is highly impacted by fisheries’ bycatch worldwide. This study updates and estimates the leatherback turtle stranding records from 2001 to 2014 in the Gulf of Venezuela. Eighty-six stranded leatherback turtles were documented in the coast of the Gulf of Venezuela. Immature leatherback turtles were the most affected (85.1%) and the highest number of strandings were recorded during the dry season (55.8%). Our findings represent the minimum estimate of stranding events for the Gulf of Venezuela, especially considering the current lack of fisheries regulations. This is the latest update for the leatherback turtle strandings in the Gulf of Venezuela and could help to create new management solutions in the area aiming to minimize the impact on leatherback turtle populations in the Caribbean.


1979 ◽  
Vol 57 (9) ◽  
pp. 1825-1829 ◽  
Author(s):  
William Threlfall

Three species of digenetic trematodes (Pyelosomum renicapite, Calycodes anthos, Cymatocarpus sp. (?)), are reported from two Atlantic leatherback turtles (Dermochelys coriacea) taken off the coast of Newfoundland and Labrador, in 1973. The status of the genera Pyelosomum Looss, 1899 and Astrorchis Poche, 1925 is discussed.


2021 ◽  
Vol 2 (2) ◽  
pp. 51
Author(s):  
Freddy Pattiselanno ◽  
Natanael Natumnea ◽  
Kuswanto Kuswanto ◽  
Muhamad Ansarudin ◽  
Yosefina M. Goban ◽  
...  

ABSTRACT Wau-Weyaf Beach is the nesting ground of six species of turtles, including the world's largest turtle, the leatherback turtle (Dermochelys coriacea). The University of Papua (UNIPA) Manokwari, since 2009 has been directly involved in the turtle nesting area protection program by involving the students of UNIPA through the Community Service Program (KKN). In 2016, students carried out the KKN Program starting from June 30th to August 16th in Kampung Wau-Weyaf, one of the leatherback turtles’ egg-laying locations in Abun. This paper is a part of the Community Service Program which is carried out in the said village. The activities conducted during the KKN include both formal and non-formal education, religious education, and environmental education. Education-based KKN directly helps to improve public awareness which, in turn, supports the efforts to protect and save the leatherback turtles (Dermochelys coriacea) on the coast of Abun, Tambrau. The same approach is also able to improve the calistung (the capability to read, write, and count) ability of school children along with their awareness to maintain the cleanliness of their homes, school, and village environment. Keywords: Education; Conservation; Turtle; Wau-Weyaf   ABSTRAK Pantai Wau-Weyaf merupakan tempat bertelur bagi 6 jenis penyu, termasuk penyu terbesar di dunia, Penyu Belimbing (Dermochelys coriacea). Universitas Papua (UNIPA) Manokwari, sejak tahun 2009 telah terlibat secara langsung dalam program perlindungan kawasan peneluran penyu ini melalui pelibatan mahasiswa melalui program Kuliah Kerja Nyata (KKN). Pada tahun 2016,  mahasiswa Universitas Papua (UNIPA) melaksanakan program KKN yang dilaksanakan antara tanggal 30 Juni sampai dengan 16 Agustus 2016 di Kampung Wau-Weyaf. Tulisan ini merupakan bagian dari pelaksanaan kegiatan KKN yang dilaksanakan di kampung Wau-Weyaf sebagai salah satu lokasi peneluran telur penyu belimbing di Abun.  Kegiatan yang dilakukan meliputi pendidikan formal dan non-formal, pendidikan agama, dan pendidikan lingkungan. KKN berbasis pendidikan yang dilakukan secara langsung membantu meningkatkan penyadar tahuan masyarakat yang menunjang usaha perlindungan dan penyelamatan penyu belimbing (Dermochelys coriacea) di pesisir Abun, Tambrau. Pendekatan yang sama juga mampu meningkatkan kemampuan calistung anak-anak sekolah dan kesadaran menjaga kebersihan lingkungan rumah, sekolah dan kampung. Kata kunci: Pendidikan; Konservasi; Penyu; Wau-Weyaf


1979 ◽  
Vol 6 (1) ◽  
pp. 105 ◽  
Author(s):  
CJ Limpus ◽  
C McLachlan

Nesting of leatherback turtles in eastern Australia is confined to low-density nesting on mainland subtropical Queensland. Measurements of adults, eggs and hatchlings from this area are presented. The species is relatively common in central eastern Australian waters though rarely sighted elsewhere in northern, eastern and southern Australia. The origin of the non-breeding eastern Australian leatherback turtles is postulated in terms of the colonies reported on the islands north of the Coral Sea.


2012 ◽  
Vol 279 (1737) ◽  
pp. 2391-2395 ◽  
Author(s):  
George L. Shillinger ◽  
Emanuele Di Lorenzo ◽  
Hao Luo ◽  
Steven J. Bograd ◽  
Elliott L. Hazen ◽  
...  

So little is known about the early life history of leatherback turtles ( Dermochelys coriacea ) from hatchling to adulthood that this period has been termed the ‘lost years’. For critically endangered eastern Pacific leatherback populations, continued and rapid declines underscore the urgent need to develop conservation strategies across all life stages. We investigate leatherback hatchling dispersal from four Mesoamerican nesting beaches using passive tracer experiments within a regional ocean modelling system. The evolution of tracer distribution from each of the nesting beaches showed the strong influence of eddy transport and coastal currents. Modelled hatchlings from Playa Grande, Costa Rica, were most likely to be entrained and transported offshore by large-scale eddies coincident with the peak leatherback nesting and hatchling emergence period. These eddies potentially serve as ‘hatchling highways’, providing a means of rapid offshore transport away from predation and a productive refuge within which newly hatched turtles can develop. We hypothesize that the most important leatherback nesting beach remaining in the eastern Pacific (Playa Grande) has been evolutionarily selected as an optimal nesting site owing to favourable ocean currents that enhance hatchling survival.


2019 ◽  
Author(s):  
E. De Andrés ◽  
Juan José Negro Balmaseda ◽  
Juan Carlos Navarro ◽  
Adolfo Marco

ABSTRACTThis study provides baseline data on fatty acid profiles and carotenoids in eggs of the leatherback sea turtle, Dermochelys coriacea. Correlations among such compounds, persistent organic pollutants, and reproductive parameters are also investigated. A number of 18 clutches were evaluated during June and August of 2008 at Reserva Pacuare Beach, in the Caribbean side of Costa Rica. Viability and fertility were calculated for each nest. Concentration levels of saturated and unsaturated fatty acids (SFAs and PUFAs), carotenoids and different congeners of persistent organic pollutants (POPs) were determined from egg-yolk samples. Mean ± SD values were calculated for each compound and for each clutch. Correlations were performed searching for interactions among different compounds and for potential effects on reproductive parameters, thus all the studied compounds were related to each other and to any of the reproductive parameters. Low carotenoid levels characterized all eggs of this species, and a positive relationship between carotenoid concentrations and the viability rate was found. POPs and PUFA were positive and strongly correlated, suggesting molecular interactions. PUFAs appeared to increase fertility rate and hatchling length. This study provides potential evidences of PUFA enhancing fertility and hatchling size, and of carotenoids limiting vitellogenesis. The positive correlation found between POPs and PUFAs may indicate that harmful effects of these contaminants on the reproduction of leatherback turtles could be masked.


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